Quantum mechanics provides us most fundamental descriptions of our most early universe, but there is a long-standing debate amongst theoretical physicists about what all these mathematics really mean in real world? The present three-dimensional (3D) universe, we humans experience daily since our birth, is probably just one of an enormous numbers of essentially classical worlds, and all quantum phenomena arise from a universal force of repulsions that prevented many universes (Multiverse) from having identical physical configurations like ours. Probabilities arise only because of our human ignorance as to which in our world an observer occupies a position in space time. This picture is all that is needed to explain bizarre quantum effects such as particles that can tunnel through solid barriers and wave behavior in double-slit experiments or in a warm hole. Our many-interacting-universes approach hinges on our assumption that interactions between deterministically evolving worlds cause all quantum effects. Each world is simply the position of particles in three-dimensional space time, and each would evolve according to Newton’s laws, if there were no inter world interactions. A surprising feature of human approach was that the formulation contains nothing that corresponds to the mysterious quantum wave functions, except in the formal mathematical limit in which the number of worlds becomes infinitely large. Conversely, Newtonian mechanics corresponds to the opposite limit of just one world. Thus, our approach should incorporate both classical and quantum theory. As few as two interacting worlds can result in quantum like effects, such as tunneling through a barrier. Many interacting worlds theory (MIW) explains that rather than standing apart, an infinite number of universes in the early time shared the same space and time as ours. They show that the theory can explain quantum mechanical effects while leaving open the choice of theory to explain the universe at large scales. This is a fascinating new variant of multiverse theory that, in a sense, creates not just a doppelganger of everyone but an infinite number of them all overlaying each other in the same space and time. The fine tuning of parameters required to reproduce our present day universe suggests that our universe may simply be a region within an eternally inflating super-region. Many other regions beyond our observable universe might have existed in earlier times with each such universe governed by a different set of physical parameters and laws. Collision between these regions, if they occurred, should have left signatures of anisotropy in the cosmic microwave background (CMB) but have not been seen yet. We assess different mechanisms for this residual emission and conclude that although there is a 30% probability that noise fluctuations may cause foregrounds to fall within 3σ of the excess, there is less than a 0.5% probability that foregrounds can explain all the excess. A plausible explanation is that the collision of our universe with an alternate universe, whose baryon to photon ratio is a factor of ∼4500 larger than ours, could produce enhanced Hydrogen Paschen-series emission at the epoch of recombination. Future spectral mapping and deeper observations at 100 and 217 GHz are needed to mitigate systematics arising from unknown galactic foregrounds and to confirm this unusual hypothesis. After careful analysis of the spectrum of the CMB, Chary et al. found a signal that was about 4500x brighter than it should have been, based on the number of protons and electrons. Scientists believe that this existed in the very early universe. Indeed, this particular signal, an emission line that arose from the formation of atoms during the era of recombination is more consistent with a universe whose ratio of matter particles to photons is about 65x greater than our own. There is a 30% chance that this mysterious signal is just noise, and not really, a signal at all; however, it is also possible that it is real, and exists as a parallel universe.